SQLite won't match C# DateTime retrieved from database

I'm attempting to run some unit tests on my application using SQLite in memory, but I've run into an odd problem:

I have two queries. The result of the first is the date of the most recent price list for a given list name, and that DateTime is used in the second query in order to fetch the most recent prices. The problem is, the second query returns no results.

Any idea what might be going wrong in the background here?

        var effective = DbSession.Current.CreateCriteria<ItemPrice>()
                .SetProjection(Projections.Max("Effective"))
                .Add(Restrictions.Le("Effective", workDate))
                .CreateCriteria("PriceList")
                .Add(Restrictions.Eq("ListName", listName))
                .Add(Restrictions.Eq("Active", true))
                .UniqueResult<DateTime>();

        return DbSession.Current.CreateCriteria<ItemPrice>()
            .Add(Restrictions.Eq("Effective", effective))
            .CreateCriteria("PriceList")
            .Add(Restrictions.Eq("ListName", listName))
            .Add(Restrictions.Eq("Active", true))
            .List<ItemPrice>();

Result: Ended up implementing a custom IUserType to store the DateTime as a string, and adding a Fluent Automapping convention for DateTime to use it (included below):

class SQLiteDateTime : IUserType
    {
        #region IUserType Members

        public object Assemble(object cached, object owner)
        {
            return cached;
        }

        public object DeepCopy(object value)
        {
            var dt = (DateTime) value;
            return new DateTime(dt.Year, dt.Month, dt.Day, dt.Hour, dt.Minute, dt.Second);
        }

        public object Disassemble(object value)
        {
            return String.Format("{0:yyyy'-'MM'-'dd' 'HH':'mm':'ss.fff}", value);
        }

        public new bool Equals(object x, object y)
        {
            return x.Equals(y);
        }

        public int GetHashCode(object x)
        {
            return x.GetHashCode();
        }

        public bool IsMutable
        {
            get { return false; }
        }

        public object NullSafeGet(ID开发者_StackOverflow社区ataReader rs, string[] names, object owner)
        { 
            string dateString = (string)NHibernateUtil.String.NullSafeGet(rs, names[0]);
            DateTime result = DateTime.ParseExact(dateString, "yyyy'-'MM'-'dd' 'HH':'mm':'ss.fff", CultureInfo.InvariantCulture.DateTimeFormat);

            return result;
        }

        public void NullSafeSet(IDbCommand cmd, object value, int index)
        {  
            if (value == null)
            {
                NHibernateUtil.String.NullSafeSet(cmd, null, index);
                return;
            }
            value = Disassemble(value);
            NHibernateUtil.String.NullSafeSet(cmd, value, index);
        }  

        public object Replace(object original, object target, object owner)
        {
            return original;
        }

        public Type ReturnedType
        {
            get { return typeof (DateTime); }
        }

        public NHibernate.SqlTypes.SqlType[] SqlTypes
        {
            get {   
            var types = new SqlType[1];  
            types[0] = new SqlType(DbType.String);  
            return types;  
            } 
        }

        #endregion
    }

Try setting a CustomType of Timestamp for that column. It's the difference between saving the milliseconds or not, I think.